GLOBAL warming could be on the verge of triggering a rise in
sea levels that would flood huge swathes of the Earth's most densely
populated regions, says an unpublished report from the world's
top climate scientists. Caused in large part by the melting of
Greenland's ice sheet, this process would take a thousand years
or more but would be "irreversible" once under way.
The report, due to be published next May by the UN's Intergovernmental
Panel on Climate Change (IPCC), is being read bv the world's goven-iments.
The final draft seen by New Scientist suggests that dozens of
the countries meeting this week to agree on global warming limits
through the Kyoto Protocol may face being wiped off the world
map. Four years ago, the IPCC forecast that sea levels could rise
by half a metre in this century and by a maximum of between 1.5
and 3 metres over the coming 500 years. The new assessment suggests
an eventual rise of 7 to 13 metres is more likely. This is enough
to drown immense areas of land and many major cities. These rises
will occur even if governments succeed in halting global warming
within the next few decades, the report says. Two factors are
causing the rise: the slow spread of heat to the ocean depths
and the destabilising of major ice sheets. It will take about
a thousand years for warming in the atmosphere to reach the bottom
of the oceans. The resulting thermal expansion "would continue
to raise sea levels for many centuries after stabilisation of
greenhouse gas concentrations". Even ff global warming is
halted within a century, thermal expansion will eventually raise
the oceans by between 0.5 and 4 metres. Even more alarming is
the fate of the ice that covers Greenland. Among all of the world's
ice sheets, this is now thought to be "the most vulnerable
to climatic warming". It contains enough snow and ice to
raise sea levels by about 7 metres if it melts. And this looks
increasingly likely to happen. Models show that after any warming
above 2.7 'C, "the Greenland ice sheet eventually disappears".
Nearly all predictions show Greenland warming more than this,
says the report, and the faster the warming, the faster the melting.
An extra 5.5 'C would cause sea levels to rise by 3 metres over
a thousand years. An 8 'C warming would cause a 6-metre rise in
sea levels in the same time. The report's authors are not allowed
to discuss their findings until publication. But Jonathan Gregory
of Britain's Hadley Centre for Climate Prediction and Research
in Bracknell, who coauthored the chapter on sea level, told New
Scientist recently that once under way, the disintegration of
the Greenland ice sheet would be "irreversible this side
of a new ice age". The fate of the West Antarctic ice sheet,
which is perched on submerged islands, remains controversial,
says the report. If it melted, it would raise sea levels by a
further 6 metres. Some experts quoted in the report predict that
the sheet could entirely disappear within 700 years. Others, supported
by the authors, expect that the sheet will contribute "no
more than 3 metres" to sea level in that time. If sea levels
were 10 metres higher than today by the year 3000, it would cause
the inundation of a total area larger than the US, with a population
of more than a billion people and most of the world's most fertile
farmland. Fred Pearce

Drugs on tap from morning dew
NS 25 Nov 2000

THE "sweat" of plants could in future yield a rich
harvest of drugs and chemicals. That is the hope of researchers
who have created tobacco plants that ooze foreign proteins from
their leaves each morning. Plants can be engineered to produce
everything from vaccines to plastics. But extracting proteins
from plant tissue is often complicated and expensive. Instead,
llya Raskin and his colleagues at Rutgers University in New Jersey
wondered if plants could excrete proteins in the "dew drops"
found on leaves. During the night, when leaves lose less moisture
by evaporation, pressure builds up inside and squeezes fluid out-a
process called guftation. This fluid contains small amounts of
protein, which Raskin guessed must come from the fluid in the
spaces between cells. So Raskin and his team genetically engineered
tobacco plants to produce three foreign proteins in this intercellular
fluid, including the green fluorescent protein from jellyfish.

Just as they hoped, the foreign proteins showed up in the dew
on the leaves. In the future, the technique might be applied to
other plants that produce large drops of guttation fluid, such
as tomatoes and grasses. The drops could be sucked or shaken off
the leaves each morning and processed to purify the proteins (Plant
Physiology, vol 124, p 927). "it would provide a system for
obtaining fluid that is already purified and concentrated,"
says Hugh Mason of Cornell University in New York, who works on
vaccine expression in potatoes. The amount of protein Raskin's
team has been able to get expressed-about 2.8 per cent of all
the protein in the guttation flui@s comparable to what other people
have been able to extract from the plant itself, says Mason. Raskin
thinks the method could be used in combination with another approach
he has pioneered for making plants release proteins from their
roots (New Scientist, 1 July, p 27). Nell Boyce, Washington DC

Taking the Plunge NS 25 Nov
2000
Our distant ancestors fondness for a swim may explain humans are
unusual primates, Kate Doualas takes a new look at a controversial
old theory

"SMASHING a paradigm is rejuvenating," says Phillip
Tobias. He should know. To mark his 70th birthday five years ago,
Tobias urged his fellow palaeoanthropologists to ditch one of
the central dogmas of human evolution-the notion that our ancestors
made their first great advance towards human form by swinging
out of the forest and into the open savannah, where they began
walking upright. "Open the window, and throw out the savannah
hypothesis," was Tobias's rallying call. Today, that paradigm
has been so thoroughly bashed that some people argue it never
really existed. But Tobias isn't finished yet. Although physically
frail, when he gets up ori the podium he has the delivery and
mental agility of a man half his age. And this giant of palaeoanthropology
is once again challenging his audience. If humanity wasn't born
out of a move into Africa's hot, open spaces, then how? "It's
time to open our minds," says Tobias, a professor at the
University of Witwatersrand in Johannesburg. He wants the academic
establishment to consider the heretical idea that we were born
of water. Forty years ago, New Scientist published a feature entitled,
"Was man more aquatic in the past?" (17 March 1960,
p 642). In it, Alister Hardy, a distinguished biological oceanographer
and Fellow of the Royal Society, went public with an idea that
he had sat on for almost three decades, fearing it would jeopardise
his career. "My thesis," he wrote, "is that a branch
of the primitive ape-stock was forced by competition from life
in the trees to feed on the seashores." Hardy argued that
if our ancestors were semi-aquatic, it might explain major physical
differences between humans and the other primates. The move into
a watery environment would account for our exceptional swimming
abilities and the fact that newborn babies can swim and float,
said Hardy. It would also have put pressure on our ancestors to
start walking upright, in order to keep their heads above water.
This in turn freed up their hands, allowing them to use tools-probably
starting simply by cracking open shellfish with stones, just as
California sea otters do today. Hardy also noted that we are the
only "naked" ape, and that loss of hair is a characteristic
of some aquatic mammals. Many such creatures have a layer of fat
just beneath the skin-another feature which distinguishes us from
other primates. Our profusion of sweat glands would then be a
counterbalance to this insulating layer, an adaptation to keep
us cool when out of the water. Maybe Hardy should have trusted
his instincts and kept quiet. He had hoped his idea might be "discussed
and tested against further lines of evidence". What he got
was the cold shoulder. The "aquatic ape" theory never
provoked anything more than derision or embarrassment among anthropologists,
and to this day only one academic exchange on the subject has
been published. Hardy quietly dropped his idea, but it was soon
picked up in a surprising quarter. From a valley in rural south
Wales, housewife and dramatist Elaine Morgan began compiling evidence
and writing books in support of the aquafic-ape theory-the first
of which appeared three decades ago. Morgan compared the anatomy,
biochemistry and physiology of modern humans with other animals,
and used these comparisons to extend Hardy's original arguments.
She pointed out, for example, that with 10 times the fat cells
you'd expect for an animal of our size, we are by far the fattest
primates. Our babies are the only ones bom fat. The subcutaneous
layer laid down during the last month of gestation grows thicker
during the first months of life. And this is white fat-not great
for insulation but an excellent aid to buoyancy. Unlike the fat
of most mammals, this fat is bonded to the skin, just as it is
in dolphins, seals, and bippos. Morgan has found several aquatic
adaptafions to add to Hardy's list. In parficular, she argued
that some of the physical traits that make speech possible evolved
as a result of living in water, rather than to improve communication
skills. Among terrestrial mammals, we alone have voluntary control
of our breathing, an ability shared by all diving mammals. Likewise,
no other land mammal has a descended larynx, which is useful for
speech but also allows a swimmer to gulp large quantities of air
quickly through the mouth. Morgan wasn't entirely surprised by
the reaction she got from the academic establishment. "They
viewed me as a crackpot. 'Farcical' was an average comment,"
she recalls. "Probably the main reason was their strong conviction
that they already had the answer." Indeed, all the evidence
that emerged during the 1970s and 1980s seemed to support the
savannah theory. Fossils were found in the hot, dry grassland
areas of South Africa and the Rift Valley, bolstering the idea
that our ancestors were "killer apes" who moved into
the open to hunt their prey. Water had no role to play in this
view of human evolution. Competition in the harsh, savannah enviroranent,
the theory held, led to an upright gait, tool-use and expanding
brainpower. But no oneincluding Tobias, once one of the strongest
proponents of this view-stopped to think that areas which are
savannah today may not have been so in the past.

Then, in the 1990s, Tobias and his colleagues finally checked.
They examined fossihsed pollen recovered with 2.7-million year-old
hominid remains from a grassland site at Sterkfontein, 50 kilometres
north-east of Johannesburg. The pollen suggested that the area
had been more wooded than was previously susp@cted. But the clincher
came with the discovery of fossilised lianasvines that hang from
forest trees. These could not have come from open savannah. Other
South African hominid sites also yielded plant and animal remains
characteristic of ancient forests. Then came similar findings
in Ethiopia, at the site where the famous "Lucy" was
found, and also alongside what is probably the oldest hominid
discovered, dating back more than 4 millim years. The inescapable
conclusion was that Ethiopia, too, was heavily wooded when our
ancestors lived there. But if human evolution wasn't kickstarted
by a move to the savannah, what could account for the emergence
of such an unusual animal? Tobias was quick off the mark in the
search for a new answer. He noticed that what all the fossil hominid
sites had in common was proximity to water. Then there was the
obvious fact that our species cannot go long without a drink,
and seems to waste large amounts of fluid in sweat and urine.
"If ever our early ancestors were savannah-dwellers they
must have been the most profligate urinators on the savannah,"
he says. We need a constant supply of water, but was there more
to it than that? Tobias is not yet sure whether water played a
decisive role in the initial split between human and chimp ancestors.
But his recent research has convinced him that by about 2 million
years ago, our ancestors were adapted to a coastal environment,
and this is what allowed them to spread across the globe. The
sea level was much lower than it is today when the first hominids
moved out of Africa, Tobias notes. Land that is now submerged
would have been exposed, allowing Homo erectus to walk from Africa
around the coast of southern Asia to Siberia. But it wasn't just
a matter of colonising the beaches. He points to two particular
finds as evidence that these immediate forerunners of Homo sapiens
were not only adapted to life on the coast, but were also at home
in the water. Just beyond the island of Bali in the Indian Ocean
lies a deep underwater trough. Even with sea levels low, there
would still have been at least 19 kilometres of water separating
Bali from the next island. Yet recently unearthed remains of ancestral
elephants and stone tools on the island of Flores, well beyond
this barrier, date back around 900,000 years. How did they get
there? It's likely that the elephants swam. Despite appearances,
elephants are strong swimmers-their record is 48 kilometres-and
they can use their trunks as snorkels. As to how the tools got
there, our own ancestors may have floated or rafted over-this
is long before the first boats appear in the archaeological record.
Or they too could have swum, says Tobias. This second possibility,
he says, is bolster-ed by hominid artefacts found in southeastem
Spain dating from 1 to 1.5 million years ago. The extreme age
of the remains suggest that Homo erectus took a short cut, swimming
across the five-kilometre-wide Strait of Gibraltar rather than
trekking through the Middle East and across mountainous southem
Europe. "Have we been swimmers for one million years?"
asks Tobias. "I believe it's very likely." It's a conservative
estimate, according to Marc Verhaegen from the Centre for Anthropological
Studies in Putte, Belgium. He points to fossil evidence from Arabia
which indicates that an ancestor of all the great apes was living
in watery forest margins 17 million years ago. Verhaegen believes
that @ animal would have waded on two legs in the water and moved
effortlessly through the trees, in much the same way as the mangrove-dwelling
proboscis monkeys of Borneo do today. Most primates find it easy
to adopt an upright gait when necessary, he says, because arboreal
adaptations have left them with a highly mobile spine and flexible
limb joints. Verhaegen also cites evidence from hominid teeth
to support the idea of a long association between apes and water.
At the Museum of Mankind in Paris, PierreFranqois Puech has been
looking at the microscopic features of the tooth enamel. Teeth
from the fossils of both eastern and southern Africa have a glossy,
polished surface typical of animals that feed on succulent marsh
and riverside vegetation. Our ancient affinity for water can also
be seen in the anatomy of our hands, Verhaegen argues. By walking
upright, the ancestral primate would have kept its hands free
for manipulating objects and climbing. This would have allowed
the hands to evolve into supremely dexterous tool-making appendages.
Verhaegen also believes that the knucklewalking we now see in
chimps and gorillas evolved later, as their forebears moved inland.
Support for this idea comes in the form of the 3.3-million-year-old
fossil hand from South Africa known as Little Foot. Its discoverer,
Ron Clarke of the University of Frankfurt, described it at a meeting
early this year as "quite modern" in form. He concluded
that the short palm and fingers suggest that Little Foot did not
knucklewalk, undermining the old notion that we are descended
from primates who did. "There's no doubt that the differences
between chimps and humans must be explained by a waterside past
which included wading and diving," Verhaegen says. And he
sees the repercussions extending right down through the ages to
our own genus. Some Neanderthals had bony outgrowths in their
ear canals. In modern humans, such ossification is only found
in lifelong divers, suggesting to Verhaegen that Homo neanderthalensis
spent much time in the water. Though Verhaegen holds an extreme
view in the debate on aquatic origins, other researchers also
see signs that we have been shaped by a watery environment. Michael
Crawford, a biochemist from the Institute of Brain Chemistry and
Human Nutrition at the University of North London and his colleagues
are convinced that without water, Homo sapiens could never have
evolved the trait that above all others makes us human: our big
brains. Fossil skulls reveal that for the first 3 million years
after the split with chimps, our ancestors' brains barely increased
in size. But then, around 2 million years ago, they began to grow
steadily. The past 200,000 years show a sudden, exponential growth,
and a 50 per cent increase in cranial capacity from Homo erectus
to Homo sapiens. "As far as the biochemistry is concerned,
I cannot see how a large brain could have evolved on the savannah,"
says Crawford. He points out that the general trend among savannah-dwellers
is towards larger bodies and smaller brains. At the extreme, a
1-tonne rhino has a 350-gram brainless than 0.1 per cent of its
body mass. Crawford believes that two particular fatty acids hold
the key. Docosahexaenoic acid (DHA) is needed to construct the
membranes of neurons and photoreceptor cells, while arachidonic
acid (AA) is a crucial component of the walls of blood vessels,
without which a large brain cannot grow or function. Crawford,
along with Andrew Sinclair from RMIT University in Melbourne and
others, has looked at the chemical composition of brains from
42 different animal species and found that they all contain the
same proportion of DHA and AA. VVhat's more, there is no substitute
for either of these fatty acids. These findings have strengthened
the researchers' suspicion that brain size is limited by the availability
of DHA and AA. Both fatty acids are in extremely short supply
and are slow to form within the body. DHA is especially rare in
the diets of large savannah-dwelling mammals. Although a precursor
of AA is found in the seeds of flowering plants, the only place
where DHA is abundant in the food chain is in the world's oceans,
lakes and rivers. This is where the first primitive nervous system
evolved. "DHA has a 600-millionyear track record," says
Crawford. Marine nutrients are likely also to have hastened the
growth of the human brain, he argues, pointing out that people
whose diets are deficient in DHA and AA suffer mental and vascular
illnesses. "No other theory which attempts to explain the
human brain offers any molecular mechanism. But there is a lot
of science in support of the right ecological niche," says
Crawford. It might explain why chimps and humans are so different
despite our remarkable genetic similarity, he adds. The earliest
fossils of modem humans found so far come from coastal sites on
the Red Sea and the southern cape of South Africa. Domestic remains
indicate that these people were eating seafood 100,000 years ago,
at the same time that the human brain was expanding. Crawford
envisages generations of people-women and children in particular-harvesting
and eating this abundant and reliable food source. This would
have directed the essential fatty acids straight to where they
could have the greatest effect. Mother's pass on DHA to their
babies through the placenta and via breast milk. VVhat's more,
recent evidence shows that bottle-fed babies who receive DHA and
AA supplements are better at problem solving than those who do
not. "Modem Homo sapiens ate fish and shenfish consistently
as a requirement for brain expansion and increased intelligence,"
says Crawford's colleague, Leigh Broadhurst from the US Department
of Agriculture near Washington DC. "The diet came first."
And it wasn't just on Aftica's coastline. Genetic analysis of
people ahve today indicates that the first modem humans arose
inland, in the Rift Valley, another place where water is central
to life. With Crawford, Claudio Galli from the University of Milan,
and others, Broadhurst has shown that people hv'mg around Lake
Turkana and Lake Nyasa still benefit from a diet rich in DHA and
AA. She also points out that there is no other environment on
Earth like this. It is the only place where tectonic drift started
to create an ocean and then the process stopped in its tracks.
Broadhurst believes that our uncommon intelligence arose out of
this unique environment. So has the scientific community finally
accepted the amateur enthusiast, Morgan? Not quite. Two years
ago, anthropologists invited her for the first time to address
a big meeting, but the majority remain sceptical. They are particularly
concemed that most of the support for her ideas comes from the
physiology and form of modem humans, not the fossil record. Even
those who like Morgan's ideas in principle say that more research
is required. Tobias argues that the theory should be renamed,
perhaps as "water and human evolution". While he and
others are quite satisfied that water played a major role, they
suspect that "aquatic-ape theory" is misleading and
will never be taken seriously. just how aquatic our ancestors
were is a thomy issue. These days, even Morgan sees no evidence
for a fully aquatic hominid. But she and her supporters can't
agree on how aquatic it actually was. "No one is able to
comn-dt to an answer," says John Langdon from the University
of Indianapolis. And then there's the problem of exactly when
this association with water occurred. "The chronology of
the aquatic-ape hypothesis does not work," says Langdon.
The traits Morgan points to as aquatic adaptations appear one
by one over a 4-million-year period. Unless humans lived largely
in the water for that entire time, Langdon argues, invoking an
aquafic phase to explain our evolution just complicates the issue.
Chris Stringer from London's Natural History Museum also downplays
the role of water. He sees coastal living as a late development,
'part of the expanding adaptive horizons of modem humans".
He has recently described a possible coastal route out of Africa,
and is especially impressed by the speed with which Homo sapiens
made the long trek to Australia. New dates indicate they arrived
at least 60,000 years ago, suggesting our seafaring abilities
are older than many anthropologists had suspected. There are still
researdiers who greet the new developments with about as much
enthusiasm as Hardy received back in 1960. But even they don't
doubt the savannah hypothesis is dead. Whether it will be replaced
by an amphibious theory remains to be seen. The fide is tun-dng,
though. "The ridicule placed at the door of the aquaticape
theory is easy to generate, just as the President of the Royal
Society ridiculed Mr Faraday's useless experimental demonstrations
of electricity," says Crawford. "Ridicule is a popular
and pohfical tool but not a scienfific tool. If you want to di0enge
a thesis, you do it with facts and science." T'he aquatic-ape
debate is at last being fought on those grounds.

Genesis of Eden Diversity
Encyclopedia

Get the Genesis
of Eden AV-CD by secure
internet order >> CLICK_HEREWindows / Mac Compatible. Includes
live video seminars, enchanting renewal songs and a thousand page
illustrated codex.

IT WASN'T just the weather that was gloomy in The Hague this
week. As governments gathered to thrash out ways to reduce the
atmosphere's burden of carbon dioxide, there was palpable pessimism
over the expected clash between Europe and the US. At issue was
the balance between countries cutting their CO, emissions and
expanding their carbon sinks. So it's good to know that if you
look in another direction, there is immense optimism that greenhouse
emissions can be cut. The key is a simple, yet radical switch
in technology to fuel cells. These reactors combine hydrogen and
oxygen to produce electricity, heat and water. That fuel cell
firms are enthusiastic about their business is hardly surprising.
But energy economists, car companies and venture capitalists are
upbeat too. They see solid projections grounded in the economics
of manufacturing industry-a welcome contrast to the dotcom mirages.
Fuel cells are efficient, clean, quiet and have few moving parts,
so what's standing in their way? Price for one thing. Though costs
have fallen (see Diagram) you still have to pay upwards of $500
for every kilowatt from a fuel cell. This is too dear for many
applications. A combined cycle gas turbine might give you a kilowatt
for $400, while car engines do the same for a stunning $50. But
there is great confidence that fuel cells will get cheaper. In
the past five years, for example, Johnson Matthey has cut the
quantity of platinum catalyst in fuel cells by a factor or 20,
and experts think they can shrink that by another factor of 5.
And fuel cells are sure to become cheaper as the economies of
mass production kick in. As these factors make their impact, fuel
cells will start to appear in a variety of guises. First, they'll
replace batteries, which are incredibly pricey for the power they
deliver. The fuel in this case will probably be methanol, and
will bring the bonus that topping up the fuel cell for your laptop
should take minutes rather than hours it takes to recharge a battery.
Within a couple of years, fuel cells will provide heat and electricity
for homes and offices. The source of hydrogen here will be natural
gas, which if it is-cheap enough will allow fuel cells to undercut
today's combination of heating boiler and mains electricity (see
New Scientist, 18 November, p 16). Larger, static fuel cells will
become attractive for hotels and sport centres, while power companies
will use them as alternatives to extending the electricity grid.
But the most visible and exciting development will come three
or four years from now when the first commercial fuel-cell buses,
trucks and cars purr onto our streets (see this week's special
report, p 34). Which fuel they will use is anyone's guess: the
big car companies are working on everything from petrol, natural
gas and methanol to pure hydrogen. Some critics see this plethora
of fuels as a problem, especially when it comes to distributing
them. Others see it as an extension of what we already have. We're
used to seeing diesel, petrol and LPG on forecourts, so why not
the others too? Fuel cells could also trans form the way we think
about fuel and power, and where they are made. The prospect exists
of producing hydrogen at home, for example, so you could fill
up your car overnight. Conversely, the fuel cell in your car could
power your home, or generate elec tricity for the grid while you're
at work. When it comes to saving the planet, using petrol as a
source of hydrogen is no better than burning petrol in an internal
combustion engine. But other fuels do bring benefits. Compared
with emissions from existing cars, methanol will cut CO, by 25
per cent; natural gas by 40 per cent. Methane produced in biogas
plants would be C02 neutral. The best option of all is, of course,
hydrogen. Though producing and storing the gas do present problems,
nobody sees them as show stoppers. Even power generators are looking
at the figures. After all, fuel for cars sells at a higher price
than electricity. According to some economists, generators could
use their electricity to crack water, store and transport the
hydrogen, and still make more profit than they do today.

In the messy real world, things rarely slot into place quite
so well. It may be that to start the fuel-cell ball rolling, governments
will have to give forecourt hydrogen some hefty tax breaks. The
surprising-and encouragingthing is that nobody from industry is
screaming for such intervention.

There's a message here for those negotiations in The Hague:
don't put all your money into carbon sinks. The American, Japanese
and German governments have invested millions in the research
that has brought fuel cells to their present state. From here
on, it's companies trying to turn a profit that will push this
green dream forward.

Kicking
the Habit NS 25 Nov 2000 NS 25 Nov 2000

Europe by 2010.

THEY'RE calling it the "Bahrain of the North". These
are exciting times in Iceland, the birthplace of the hydrogen
economy. T'horsteinn Sigfusson, professor of physics at the University
of Iceland in Reykjavik and chairman of Iceland New Energy, says
that within 20 years his country can become the first in the world
to run on hydrogen without recourse to fossil fuels. To start
with, hydrogen will run its fleets of buses, trucks, cars and
trawlers, and later it will provide electricity and heat its buildings
through the long winters. Iceland could be the first of the 21st-century
successors to the OPEC sheikhdoms. Call them HYPEC-the organisation
of Hydrogen Producing Countries. It's early days yet, Sigfusson
admits. The first three hydrogen-fuelled buses won't hit the streets
of Reykjavik until 2002. That's several years after Vancouver
and Chicago introduced theirs. But Iceland's buses are the start
of something much bigger. Unlike most hydrogen-powered buses,
which fill up with hydrogen derived from old fuels sudi as oil,
Reykjavik's buses will run on hydrogen made by splitting water,
using hydroelectricity generated from Iceland's raging rivers.
The umbilical cord to fossil fuels will be cut. Since Iceland
has a population of only 276,000, and you can't drive there from
anywhere else, it is an ideal place to test out a future world
where cars are no longer environmental pariahs, where urban smogs
and greenhouse gases are banished. A world, in short, that has
kicked the carbon habit. Ask anyone with a stake in the energy
economy if the revolution is really necessary and they will say
yes. There are compelling reasons for change. Emissions of carbon
dioxide from intemal combustion engines are stoking the greenhouse
effect. Bun-dng oil fills our cities with smogs that kfll hundreds
of thousands every year. Technological improvements to cut emissions
from conventional cars cannot keep pace with the rising tide of
vehicles. There will probably be a bilhon on the world's roads
by 2020-one for every seven people. Meanwhile, the ofl economy
is starting to give us a bumpy ride. Nations the world over remain
shackled to OPEC-A risky position to be in, as the price hikes
of the past six months have shown. It doesn't take mudi to rock
a government and threaten global recession. And one day the oil
will run out. Oil geologist Colin Campbell was quoted in New Scientist
last year as saying that "the world's oil companies are now
finding only one barrel of oil for every four that we consume"
(10 July 1999, p 49). Even big oil companies now concede that
we cannot carry on bunting oil as we have in the past. "If
the motor car is to stay with us, we neod to explore radical new
ways to fuel it," says Paul Histon, fuels technology manager
at BP Amoco's oil technology centre in Sunbury-on-Thames near
London. "If we are truly to get big CO, reductions, hydrogen
is the best long-term choice."

Why hydrogen? Well, it's ubiquitous, inexhaustible and clean.
You can drive across the US on hydrogen without adding to the
atmosphere anything more noxious than a bathtub-full of water.
Back in 1874, Jules Veme argued in The Mysterious Island that
when fossil fuels run out, hydrogen "will furnish an inexhausfible
source of heat and light". Hydrogen's time seems to have
come.

Samy fears

But is it safe? Some industrialists argue that storing hydrogen
on filling stafion forecourts or in vehicle tanks is too dangerous.
The image of the 1937 Hindenburg airship disaster still looms
large. This is curious. The hydrogen filling the airship did not
explode, and the 35 dead were either killed by bun-dng diesel
or jumped to their deaths. In 1997, a retired NASA scientist found
that the real culprit was the flammable fabric of the airship's
outer skin, not the hydrogen. And let's not forget that cars are
already carrying round tanks of dangerously explosive liquid,
so it's really a quesfion of comparative risk. Hydrogen is easy
to ignite, but it's buoyant and dissipates rapidly. And if it
is caught in a confined space, it requires more oxygen to bum
than oil does. "Hydrogen is less hazardous than gasoline,"
says Amory Lovins of the non-profit Rocky Mountain Institute in
Colorado, which spedahses in the future design of cars. T'he key
questions today are not so much "Do we want a hydrogen economy?",
as 'What sort of hydrogen economy do we want, and how do we get
there?" Do we make the new wonder-fuel from petrol, natural
gas, methanol, biomass or water? Do we make it in centralised
hydrogen factories, on the forecourts of service stations or under
the bonnet? How do we store it? And do we put it in conventional
internal combustion engines or fuel cells? The world's biggest
car makers are busy drafting a road map to the hydrogenfuelled
future. But nobody yet seems sure of the way. BMW is betting on
an intemal combustion engine that bums hydrogen, claiming it's
the only way to deliver the acceleration and responsiveness drivers
are used to. But most believe that the intemal combustion engine,
with its Heath-Robinson assembly of transmission and drive shafts,
is too inefficient. It converts barely 20 per cent of its fuel's
energy into traction. Electric engines can have an efficiency
of up to 80 per cent. But batteries don't deliver enough power
for their weight and need frequent recharging. So attention is
increasingly focusing on electric engines without batteries. Plan
A, the so-called hybrid engine, has already been on Japanese roads
for three years, under the bonnet of Toyota's Prius model. It's
a petrol-buming engine hooked up to an electric motor. The engine
doesn't drive the car directly, but generates electricity, which
is stored in a battery and released as necessary to drive the
car. So the petrel engine can always operate at its most efficient
speed, rather than surging or slowing to the demands of road and
driver. Result: fuel savings of 10 to 20 per cent and similarly
reduced pollution. It's a start. Further improvements could be
made if the engine burnt a cleaner fuel. But the smart money is
on something more radical. That something was invented way back
in 1839 by Welsh physicist Sir Wilham Grove: a fuel cell that
runs on hydrogen. Many types of fuel cell have been developed
over the years (see "Fuelling the future", p 38). But
until recently they were too large, cumbersome and low on power
to run a carc even after NASA tinkered with them to provide pollution-free
electricity inside the Apollo spacecraft. T'he breakthrough came
in the mid-1990s when a small company, Ballard Power Systems of
Vancouver in Canada, dramatically improved their power-to-volume
ratio. Up to that point, fuel cells delivered around 167 watts
per litre. A car engine built with these would commandeer the
entire boot and back seat. Around five years ago Ballard achieved
1000 watts per litre. For the first time, fuel cells could fit
under the bonnet. The company's latest cell, the "Mark 900",
delivers 1310 watts per litre, powerful enough to make a 75 kilowatt
(100 brake horsepower) engine that fits comfortably inside a car.

Fuel cell engines are now compact enoiugh to fit into a small
car.

Soon fuel cells will be on the highways. Ballard vice-president
Paul Lancaster promises that by 2004 a quarter of a million fuel
cells will be rolling out of its $400 million production plant
every year. And he has development deals to put them in cars made
by Ford, General Motors, Toyota, DaimlerChrysler, Nissan and Honda.
Ferdinand Panik, director of DaimierChrysler's fuel-cell project
in Germany, reckons hydrogen fuel cells will power a quarter of
new cars worldwide by 2020. It could be a lot sooner, especially
now oil comPanies are @g up too. Shell gave its blessing Wt Mardi
when Don Huberts duef executive of Shell Hydrogen in Amsterdam,
predicted hydrogen would be the world's number one fuel in the
21st century. Ballard's proton exchange membrane fuel cell converts
fuel into power twice as efficiently as an intemal combustion
engine while producing no noise or noxious emissions. No wonder
hydrogen fuel cells have a green halo. British transport minister
Gus MacDonald declared in December last year that fuel cells would
allow more than half of new British cars to be "Pollution-free'
within a decade. But hang on a moment. Fuel cells are a major
advance because they are a more efficient way of powering a vehide.
But "pollution-free" they are not. This is what we might
call the "electric kettle problem". Fuel cells, like
electric kettles, emit only steam. But kettles ar-e powered by
electricity generated in power stations that bum coal or ofl.
And fuel cells are powered by hydrogen made by ... well, by what?
You cannot mine hydrogen or pluck it from the air. It has to be
manufactured. And the method of manufacture determines the pollution.
"If we make hydrogen from the wrong fuel source, sudi as
gasoline, the green halo could vanish," says Rob Macintosh
of the Pernbim Institute for APPropriate Development in Alberta.
There are two main ways of producing hydrogen. The first is electrolysis,
passing an electric current through water to split it into hydrogen
and oxygen. This requires large amounts of electricity, most of
which is generated by burning fossil fuels such as coal or oil.
Use this to run a car and there's little, ff any, gain. To make
environmental sense, the electricity has to be generated from
renewable resources (see "Make hydrogen while the Sun shines-,
p 40). T'he second route to hydrogen is to refine it@ither from
a conventional hydrocarbon or a novel source such as plant matter.
This refining, or "steam reforming-, can be done in a number
of ways: centrally at a refinery for delivery by piperine to service
stations; at the filling station itself, using hydrocarbons trucked
or piped in; or on-board the car in a small "reformer"
that directly supplies the fuel cen. In each case, reforming co@bines
a hydrocarbon and water at high temperatures to produce carbon
dioxide and hydrogen. The trick, in environmental terms, is to
choose a hydrocarbon that produces maximum hydrogen for minimum
carbon dioxide. Natural gas, which is mostly methane (CH4), is
the best because it has the highest possible hydrogen-to-carbon
ratio.

Solar Hydrogen Coachella Valley California

There are other potential methods of hydrogen manufacture,
such as mimicking photosynthesis, using heat or high-energy particles
to split water, or even hamessing bacterial enzymes. But all are
still largely confined'to the lab. Reforming natural gas, however,
is already widely used in the production of chemicals. But which
of the options would be best for the environment? Macintosh accepts
that 'to be truly pollution-free, the hydrogen must come from
a renewable source, such as solar or wind power". The green
dream of electrolysis using a renewable energy source is technically
feasible, but not yet economically viable. So Macintosh has analysed
available technologies, using the test of how much greenhouse
gas would result from making and using the fuel needed to drive
a standard vehicle-a Mercedes A-class hatchback@n a 1000-kilometre
drive across Canada. Worst, not unexpectedly, was the regular
gasoline-burning car. It emitted 248 kilograms of C02, most of
it in the exhaust gases. Next worst was a fuel-cell car with an
on-board reformer that turned gasoline into hydrogen. This so-called
"poflutionfree" vehicle chalked up 193 kilograms, mostly
from the reformer. After that came on-board reforming of me@ol,
the diemical many fuel-cell pioneers see as the most likely route
to mass-produced fuel-cell cars. In Macintosh's study, methanol
outperformed gaso@e, producing 170 kilograms of CO,. But it lagged
way behind the vehicles carrying hydrogen made from natural gas
reformed either on forecourts or at a central facility. These
emitted between 70 and 80 kilograms of CO,70 per cent less than
gasoline. Macintosh only looked at greenhouse gas emissions, but
he reported that smog-creating en-dssions would show a siniflar
profile. Even if the problem of hydrogen generation is cracked,
there are still roadblocks between here and a hydrogen economy
One is storage (see "Where to keep it-, p 41). Another is
the need to create a new infrastructure for producing and distributing
bulk hydrogen, costing perhaps @ons of dollars. This looks especially
problematic, but there are potential solutions. One is kick-starting
the hydrogen economy in smog hot spots, such as southem California,
or in areas of abundant "green" energy for hydrogen
production, such as Iceland. Another is to make the transition
in stages, perhaps by concentrating first on fuel-cell vehicles
with on-board hydrocarbon reformers. But which hydrocarbon would
make the best stepping stone? Much of the car industry favours
methanol. The argument is that methanol is a liquid, so is easier
to manufacture and handle in bulk than hydrogen while still offering
significant environmental advantages over oil. Last year, Ballard
signed a deal with Methanex of Vancouver, the world's largest
methanol producer, to set up a prototype distribution system in
Canada. Ballard is backing a similar project in the US along with
the Califomia Air Resources Board, Ford and DaimlerChrysler. Macintosh,
though, says this is misguided. "Unfortunately, on-board
processing of methanol fuel does not offer anything near to the
life-cycle greenhouse gas advantage of natural gas reforming,"
he says. It also requires a whole extra stage of manufacture a
reformer in every car, and its own distribution and storage systems.
Methanol is corrosive so would have to be held in reinforced tanks.
It's also water soluble, which means leaks into groundwater would
be hard to contain. Paul Histon of BP Amoco fears setting up a
system for shipping methanol round the country, only to have to
move again to a hydrogen distribution system a few years later.
"We only want one big change," he says. "ff it's
going to be hydrogen, let's get on and do it." The logical
solution, argues Macintosh, is for cars to fill up with hydrogen
produced on garage forecourts from natural gas. This is cheap,
because the naturalgas distribution network is already in place.
It is the most environmentally friendly technology currently available.
And it is very easy. Indeed, you might not even need filling stations.
Your office or neighbourhood could do it (see "Fill 'er up",
p 42). A reformer the size of a water heater "can produce
enough hydrogen to serve the fuel cells in dozens of cars",
says Amory Lovins. The scenario is also flexible.

BMW hydrogen filling stations planned to span Europe

As demand grows, bulk suppliers of hydrogen might get interested,
developing pipeline networks if they felt they could, undercut
local production. Natural gas, says Lovins, offers "a long
bridge to a fully renewable energy system". And there could
be unexpected bonuses along the way Robert H. Williams of Princeton
University's Center for Energy & Environmental Studies, sees
potential for the owners of gas fields tuming their product into
hydrogen at the wellhead. That way, the resulting C02 emissions
could be injected right back into the emptying well. But joumey's
end wig be a true hydrogen economy, in which the link to fossil
fuels has been cut for good. Greens and industrialists alike are
beginning to glimpse the day when renewable energywhether solar
or wind, geothermal or hydroelectric-is ready to take over electrolytic
production of hydrogen from water. Indeed, manufacturing hydrogen
may tum out to be the most effective use of renewable energy.
For it gets round the inconveniently intermittent nature of many
sources-available only when the wind is blowing or the Sun is
out. Hydrogen witl, in effect, be able to store that energy. Lovins
sees hydroelectric dams, in particular, becon-dng 'hydro-gen"
plants. They have the unique advantage of bringing together abundant
water and electricity supplies and could "eam far higher
profits by selling not electricity but hydrogen-in effect shipping
each electron with a proton attached'. This strategy even gets
round one of the major problems of hydroelectricity-the need to
flood large areas of land to store water. Reservoirs are only
needed so that electricity can be generated on demand. But the
need disappears if that electricity can be generated "at
nature's convenience"-varying according to rainfalland its
energy stored as hydrogen. Large reservoirs could be replaced
in many places by "run-of-river" hydroelectric plants
that take power from passing water without damming it. T'he hydrogen
age could be closer than we think. Certainly, the route map is
slowly emerging. But who will get on the road first? Right now,
revving up at the front of the grid is the country with one of
the largest hydroelectric reserves in the world. Plucky keland.
Fred Pearce

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